After a briefing with his top security officials, Prime Minister David Cameron suggested that the training exercises carried out by police and security officers be refined to acknowledge specific elements from the Paris attacks.

Regular training already includes “scenarios similar to the incidents in Paris,” a statement from the prime minister’s office said after the meeting. In the future, however, “the relevant agencies should identify whether there are any further specific elements of the Paris attack that should be built into the exercise scenarios.”

As France deployed thousands of troops to protect sensitive sites, Mr. Cameron asked the police in his country to work closely with the military to ensure that “appropriate military assistance” can be called upon when required. He also urged greater efforts to prevent the illegal smuggling that allowed the militants in Paris to obtain weapons that included automatic rifles.

Mr. Cameron, who had joined other global leaders for a mass solidarity rally in Paris on Sunday, also expressed his determination to give intelligence services more powers to intercept the communications of terrorism suspects.

A communications bill, previously blocked by his junior coalition partner, the Liberal Democrats, may be revived if Mr. Cameron’s Conservative Party wins re-election in May.

“The first duty of any government is to keep our country and our people safe,” Mr. Cameron said at an event in Nottingham, England, where he was delivering a speech on the economy. “If I am prime minister, I will make sure we do not allow terrorists safe space to communicate with each other.”

His comments came after the head of Britain’s domestic intelligence service MI5, Andrew Parker, called on Thursday for greater authority, arguing that digital surveillance was an essential prevention tool. Three attacks that would “certainly” have resulted in death have been foiled in recent months, Mr. Parker said.

Technology companies, in a standoff with governments ever since the revelations of mass surveillance by the former National Security Agency contractor Edward J. Snowden, have insisted that security services should make their case before a judge and obtain warrants before being given access to user data. Some privacy advocates, meanwhile, have challenged intelligence services to provide evidence both of identified plots and the role that digital surveillance played in preventing them.

Britain’s terrorism threat level, which is set by the Joint Terrorism Analysis Center, has been at “severe,” its second-highest level, since August. The only remaining level is “critical,” which would signal that an attack is imminent.